Polystyrene can be made from benzene in the series of steps shown - AQA - A-Level Chemistry - Question 6 - 2020 - Paper 2
Question 6
Polystyrene can be made from benzene in the series of steps shown.
**Step 1:** Benzene reacts with a suitable acylating agent.
**Step 2:** The organic product of... show full transcript
Worked Solution & Example Answer:Polystyrene can be made from benzene in the series of steps shown - AQA - A-Level Chemistry - Question 6 - 2020 - Paper 2
Step 1
State the type of reaction in step 1.
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Answer
The type of reaction in step 1 is acylation.
Step 2
Identify the reagent(s) and conditions needed for step 1.
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Answer
Reagents: Chloroacetic acid or Ethanoyl chloride.
Conditions: Anhydrous conditions, possibly using aluminum chloride as a catalyst.
Step 3
State the name of the mechanism for the reaction in step 2.
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The mechanism for the reaction in step 2 is nucleophilic addition.
Step 4
Identify the inorganic reagent needed for step 2.
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The inorganic reagent needed for step 2 is sodium borohydride (NaBH4).
Step 5
Name the organic product of step 2.
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The organic product of step 2 is 1-phenyl ethanol.
Step 6
Outline the mechanism for step 3.
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The mechanism for step 3 involves electrophilic substitution where the organic product undergoes a reaction with concentrated sulfuric acid, leading to the generation of a carbocation intermediate, followed by the loss of water and the formation of polystyrene.
Step 7
Draw the repeating unit of polystyrene.
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Answer
The repeating unit of polystyrene can be represented as follows:
C H
\ /
C
/ \
C H
/ \
C C
\ /
C H
\ /
C
This structure depicts the backbone of polystyrene with phenyl groups attached.
